A roundtable discussion on the state of dental digital imaging with Drs. Claudio Levato, Gordon Christensen, Dale Miles, Alan Farman, Jeffrey Dalin and Christos Angelopoulos
We can trace the digital revolution in dentistry back two decades to the time the first direct digital sensor captured a clinically acceptable diagnostic image of tooth structure. Since then, advances in digital imaging have made the technology available to every dental practice, and, indeed, driven past it to today’s advanced 3D imaging solutions. Experts and dentists who have adapted to digital imaging say the results, efficiency, patient education potential and return on investment are all greater than traditional radiographic systems. Yet less than one-third of dental practices have adapted to digital imaging.
To get to the bottom of this conundrum, we invited five of the leading clinicians and researchers in dental digital imaging to engage in a discussion exclusively for Dentalcompare readers. The result is an engaging, dynamic, thoughtful, and at times, irreverent exchange that I believe will convert even the most die-hard film fan. Our deepest thanks go to Drs. Claudio Levato, Dentalcompare Technology Editor, international lecturer and author; Gordon Christensen, possibly the world’s most recognized clinician, founder and director of Practical Clinical Courses and educator and Dean of the Scottsdale Center for Dentistry; Dale Miles, respected radiologist and educator; Alan Farman, radiologist and professor at the University of Louisville; Jeffrey Dalin, clinician and lecturer; and Christos Angelopoulos, radiologist and associate professor at Columbia University, for taking the time to take part in our roundtable.
– Steven Diogo
Steven Diogo: How has digital radiography changed the way dentists approach diagnosis, treatment planning and working with referring colleagues? Do you believe digital radiology should be the standard of care for radiographic applications in dentistry?
Dr. Claudio Levato: If you have incorporated digital radiology into your practice you have already changed your approach to diagnosis, treatment planning and communication with referrals. The degree of implementation varies significantly and I think that most dentists have only touched the peak of the iceberg. The full power of using digital images is an ongoing process, which continues to reap rewards for those willing to invest in learning how to acquire excellent images and to use the tools within the software to extract the additional information to enhance their diagnostic skills. Once you have a digital image your ability to share that image for patient education or professional communication is immediate and powerful.
I believe that digital radiology will soon become the standard of care primarily from pressure from third party payers and political pressures to have a comprehensive digital medical record.
Dr. Gordon Christensen: I agree that digital radiography is rapidly becoming state-of-the-art, but a few more years will be required to finalize this change in America. Many countries are ahead of us.
Dr. Dale Miles: Over the past five years, from the feedback I’ve received from over 50 lectures on digital technology, including hands-on image processing programs to teach dental colleagues to use diagnostic software tools, it’s clear to me that only a small percentage of dentists really understand how to apply the tools in their software to detect disease more precisely. You have to know how to apply a software filter in order to assist your clinical decision-making.
The commercial vendors have not taught dentists how the tools are to be applied, only where the tool is on the toolbar and what it does. It’s not really the vendor’s fault, because they aren’t clinicians. They know how to “turn on” an embossing filter for example, but they do not know how best to use it. And really, none of their embossing filters work very well at all, because they had a software programmer select only one direction from which to artificially create shadowing to highlight a particular surface. Not all interproximal carious lesions are on the distal surfaces of teeth! You need to be able to “light” the surfaces from different directions to allow the shadowing of the defect to be displayed and thus detected. So, in answer to your question, dentists are really at the front end of understanding the applications of the tools, so I do not believe that the diagnostic aspect has really been adopted because it’s so poorly understood. For more on that you read my article.
By the same token, you cannot be doing precise treatment planning if you haven’t really improved your detection of the disease changes. So I’m afraid, here also, the power of digital radiography/radiology is under-used and to some extent under-appreciated. Certainly, when some clinicians are able to display the changes more clearly with some tools, they can educate their patients more efficiently. So, in that respect, I believe it’s been a significant improvement over film. Just look at the size of the monitor display for a cavity on an interproximal tooth surface. The patient can now actually see the lesion because of the size and the ability to improve the image contrast and density. It’s like looking at television now. They get it!
As for communicating with colleagues, digital images have vastly improved this area. But, here again, some dentists are attempting to send hard copy images on paper to their colleagues! Why bother? The image quality is usually poor because they don’t understand that plain paper and a cheap printer cannot possibly reproduce the monitor quality. If you’re going digital, do it right. Send the image electronically in the proper file format like a Tiff file or better yet DICOM format. The clinician you send it to should also be digital and look at the image as a soft copy on his/her monitor.
Finally, yes, I’ve believed and preached that digital radiographic imaging will become the standard of care. Visit my Web site and read the 25 or so articles to see why. I believe this. I get about 50,000 to 60,000 hits per month or 1,600 visitors who believe it as well.
Dr. Jeffrey Dalin: Digital radiography is undoubtedly the standard of care for radiographic applications in dentistry. We can take better images of our patients’ teeth at lower radiation than with conventional film. Instead of looking at something 1 ½ inches by 1 ½ inches, we are able to look at something the size of a computer monitor. And there is no waiting while a film is developed, nor chemicals to deal with. We are able to enhance images we take, thus allowing us to make better diagnoses. We are able to discuss these images better with our patients, causing a higher treatment acceptance percentage. With a few clicks of a mouse, we are able to e-mail a copy of the image taken to specialists we work with.
Dr. Alan Farman: Digital 2D radiography has had limited impact on diagnosis for dentists; rather, it has improved workflow, archiving and retrieval of images, and solid state sensors have greatly improved on time usage and instant results.
Dr. Christos Angelopoulos: Digital radiography significantly contributes to diagnosis, standardization of radiographic images and good record keeping and communication with other physicians. Although digital radiographic images are the same projectional images as the film-based radiographs are—meaning their limitations associated with the projectional nature are not corrected. But the elimination of darkroom procedures, the neat and organized storage solutions, the unaffected (by time) image quality, the various image processing tools available and last the sharing of the digital images with other clinicians really distinguished digital dental imaging from the film-based one. 
In my opinion, the standard of care for radiographic procedures should include all those imaging options that ensure the highest of diagnostic image quality at the lowest possible risk for patients. If we call digital radiography the “standard of care” that will instantly make film-based imaging a substandard diagnostic imaging option, which would not be right. Film-based imaging, if properly made, can result in images of high quality, can reduce the risk to the patient substantially (if all required precautions are taken) and can serve as an adequate archiving platform if radiographs are properly processed and stored. It’s the fact that several of the factors mentioned are neglected in the film-based clinical practice that made digital radiography a better option.
Diogo: Less than one-third of practices currently use digital radiography, despite the fact that the technology has been around for two decades and several high-quality systems are available. The bugs have mostly been worked out, and there’s little chance that prices will fall based on the limited number of systems that manufactured each years. So what is keeping more dentists from incorporating digital radiography into dental practice?
Levato: I have been lecturing on digital radiography for 15 years, and I always ask the attendees why they have not incorporated digital radiology into their practices: The overwhelming answer always relates to cost. This is a valid concern, but there are numerous ROI formulas that all point to the fact that if you properly use the system, it will pay for itself. The real answer to this question is fear — the risk of making an investment and the fear of not learning how to maximize its potential. The only way to overcome this is through educating our colleagues on the many ways that this technology can help them in their daily operations. Until they can see and feel the tangible benefits they will continue to sit on the sidelines.
Christensen: The cost is too high for most dentists, and most see the sensors as too large and thick. But the simple answer is that dentists are satisfied with analog radiography.
Miles: Good Lord, have I got to answer this again in a space of two paragraphs?! There are no real obstacles, only perceived ones. Money: Not an obstacle. The ROI is rapid and guaranteed. Wired sensor: Not an obstacle. It’s a training issue requiring some staff to be re-educated, and preferably not by their dentist. Computers: Not an obstacle — used to be, but now we cannot live without them in a contemporary practice. The primary reason dentists have NOT gone digital in the radiology portion of their practice is because DENTISTS DON’T DO IT! Dentists DON’T PERFORM THE IMAGE ACQUISITION! My strong belief and observation is that if a dentist had to place and expose his or her own radiographs, had to pick up the tools to do this like using a handpiece, air abrasion unit, or laser these dentists would have thrown out their film years ago and we wouldn’t still be answering these questions! And don’t even get me started on film processing!
So, to overcome the obstacles, educate dentists to understand that if they put the digital x-ray tools in the hands of their auxiliaries and have them trained properly, they will kick themselves for not having adapted 10 years ago. They are all losing time and money being resistant because they don’t understand it.
Dalin: I agree completely. There really are no major obstacles in incorporating digital radiography into any dental practice. Laptop computers can be used if there is no existing hardware network. Price seems to be the “stopping point” of most practitioners. This is a misconception, because changing to digital will more than pay for itself in the savings from not having to purchase film and chemicals, and for the savings from spending less time developing films and waiting for a film to be brought in for evaluation.
Farman: Really, the major obstacle is the stubborn nature of mature dentists in the United States and their uncertainty regarding when they will retire. The question is whether the return on investment will be a benefit given the time left to practice. Many are set in their ways, as are their assistants. The trend that will offset this ostrich mentality is successful competition from new graduates and patients’ demands.
Angelopoulos: In my opinion, the obstacles in incorporating digital imaging into the dental office are the following:
- The fear of converting our practices into something new. Change always comes with some frustrations and worries and the comfort of using something that has worked well for so long makes changes even harder.
- The cost of the conversion.
- Long learning curve for clinicians and staff.
Diogo: If the major obstacle is dentists who don’t want to change, and the solution is the advanced technological sophistication of new dentists, then how well are dental schools preparing students for digital practice solutions? What emphasis should be placed on digital radiology in dental education?
Levato: As a general rule I believe dental schools want to bring their curriculum and facilities up to speed with technology, but their challenges are much greater than those of a private practitioner. That being said, it is still an excuse, and serious planning should be undertaken. There is no reason why the curriculum should not be updated even if the facility is not. Students need to learn a great deal more about the new diagnostic applications and how to use them before they are released into a society that is becoming very digitally sophisticated. Dentistry is much more than drilling, filling, and billing. With the recent flood of CBCT vendors into the market, and, thanks to the Internet, the public’s increasing knowledge of new technologies and applications, our students need to be prepared to learn diagnosis and treatment planning in three dimensions. In short, radiology and diagnostic imaging should be a cornerstone of the core curriculum.
Christensen: Because of a lack of funding, most dental schools are lagging in this area. Eventually, dental education will lead, but they need to get the devices into the schools.
Miles: Ooooh, here’s a loaded question. Some great. Some good. Some just giving lip service to the change. First of all, many schools, because the administrations are just as poorly prepared or haven’t planned for technology upgrades – guys, it’s like oil changes or new tires – are begging alumni, or not filling vacant faculty positions in order to garner enough revenue to pay for the transition. I taught at six different dental schools, and none really plan well or put aside money for technology improvements. They all start funding campaigns or drives, and since many schools have alums that did not have such a great experience in dental school with teachers who, to this day, do not treat students as professional colleagues, (remember faculty – they are our colleagues, they’re just at different skill level), the campaigns in many cases do not raise the capital. Those colleagues of mine who are administrators, PLAN FOR UPGRADES! That means set aside budget funds monthly to grow a technology account. Now that that’s out of the way, here’s what should happen in dental schools.
- Dental students should learn positioning using sensors.
- Dental students need only lectures on film processing.
- Dental students should have image processing labs; electronic image processing, that is.
- Dental students should learn the following: image intensification, digital radiology, medical CT and CBCT and some principles of MRI.
- Dental students should learn about PACS and DICOM.
- Dental students should re-learn head and neck anatomy as seen on all types of 2D and 3D CBCT images.
- Dental students should learn about image file formats, image storage and image compression.
- Dental students should then teach the faculty all this!! (just kidding!)
Dalin: I am happy to see that more and more dental schools are exposing their students to this superior method of taking radiographs. I feel that the majority of instruction time should be spent with digital sensors and less time with film and manual/automatic processing.
Farman: The schools are poor examples of general practice as they are built upon models that provide information for large scale “hospital” environments and need to keep check of such unimportant practice factors as student grades. Most schools do not use anything like a true dental practice environment in terms of practice management software and its necessary interaction with digital imaging systems. The ADEA is a school and not a business or health-care organization. Deans are polluted by “groupthink” from ADEA.
Angelopoulos: The dental schools that have already implemented digital radiography and electronic records are preparing students fairly well for digital solutions in general. In my experience, though, certain limitations (mainly time-related) in the curricula prevent the teaching of all available options in digital solutions. As a result most of the dental graduates have adequate training in the system or systems their school has implemented or used, and very little on other options. Also, it is not uncommon that the school will continue dedicating a considerable part of the didactic on film-based imaging even if digital imaging has been implemented, simply because dental examining bodies have not yet moved forward with including digital imaging applications in their practice and examinations.
Diogo: An early perception that digital radiography was inferior to film in image quality and diagnostic capacity is still persistent in some discussions, is this a valid concern?
Levato: I believe the published dental literature has addressed this question and the there are no diagnostic limitations on digital applications.
Miles: No. Dentists could access hundreds, yes hundreds of my radiology colleagues’ articles available worldwide to see that there is NO loss of diagnostic capability.
Dalin: This is not a valid concern any longer. Newer generation sensors take superior images in my opinion. One of the major advantages of a digital image is the ability to take an image and enhance it in the many different ways the software allows. You can enlarge certain parts of the image, you can lighten or darken the image, you can enhance the image using software algorithms, and more.
Christensen: In my experience, you have to use these tools in order to attain an image that is superior to film.
Farman: This is scientifically proven not to be a current concern. There is also much less corporate propaganda along these lines since major film producers have also begun to provide digital options.
Angelopoulos: Several scientific works have published over the last 10 years dealing with such a comparison. The vast majority of them found no statistically significant differences between film-based imaging and digital imaging as far as it concerns image quality and diagnostic efficacy. So, in my opinion, it is safe to say that such a concern is no longer valid.
Diogo: Is there a need for film based dentistry in dental practice? Can a digital solution be sufficient for all necessary general applications?
Levato: I do not believe film is needed for the practice of dentistry. There are multiple digital radiographic solutions that can meet the diagnostic requirements for all dental applications, and new diagnostic imaging applications, like Quantitative Light –induced Fluorescence (QLF) or Optical Coherence Tomography (OCT) involve computer or digital media.
Christensen: I haven’t used analog radiographs for eight years.
Miles: There is no need for film, except in developing countries that lack infrastructure and money to implement digital technology.
I see more use of panoramic imaging, especially those devices that allow pre-display image reconstruction of bitewing and periapical images. Panoramic machines are beginning to be able to “open the contacts” in the bicuspid region by employing a C-arm in the machine to allow a different rotational path for image capture. The “Super Bitewings,” as I call them, give both bitewing and periapical regions at nine line-pairs-per-millimeter resolution.
Also when wireless sensors are perfected, the “switch” to portable x-ray generators will escalate and there will be no need to hang a fixed x-ray head on an arm in an operatory. So with CBCT capability and adoption, portable x-ray generators and “full-featured” panoramics, all digital imaging will be rapid, easy and profitable.
Dalin: In my office, there is no longer any need for film based dentistry. I have a hardware network set up throughout my office. If any of our operatory computers are down or if the network is down, a laptop can be used to take and store images until everything is back up and running again. We also use a digital panoramic unit.
Farman: There is no need at all for film in current dental practice.
Angelopoulos: I think that the advancement of digital technology is such that it can fully replace all aspects of film-based dental imaging. Digital solutions are more than sufficient for general dental imaging applications.
Diogo: So, with CBCT becoming such a hot topic in dentistry, will this technology make intraoral and extraoral digital applications obsolete or will they work together?
Levato: Digital intraoral radiology is over 20 years old and is used by less than a third of the dental profession; it is a hard to imagine how long it would take for 3-dimensional imaging to become the standard. Actually, CBCT is not a competitor for intraoral and extraoral digital radiographic systems; they are all very complementary. There are specific indications for each modality. Remember the ALARA (As Low As Reasonably Achievable) concept is a cornerstone for diagnostic imaging.
Christensen: Not unless it comes down in price. At this time, cone beam is for schools, clinics, public health facilities, etc.
Miles: I explained this above. But believe me, cone beam technology will NOT replace intraoral or panoramic technology, just complement it. No one wants to wait for image reconstruction to see the results. And no one wants to have to scroll through 300 to 500 image slices to get the information to make a clinical decision. No one except we radiologists, that is: I love to look through all that data (99 MB to 250 MB per patient). And I like to be paid for that expertise. I’ve read over 1,100 CBCT cases to date. There are at least two reportable findings per scan. I and many of my radiology colleagues help reduce the dentist’s liability by reviewing the CBCT data for occult pathology. We are finally moving to the medical model of imaging in dentistry. I only wish I were 15 years younger! By the way, the findings on CBCT of the first 380 cases I looked at are also in an article on my Web site. There is a cone beam section.
Dalin: It’s exciting technology but if dentists complain about the cost of a digital sensor, they will certainly complain about the $175,000 price tag of CBCT units. These units are used more in implants and surgical situations, not for looking for decay, bone problems, and nerve issues. That might change once the price point comes down.
Angelopoulos: I think that CBCT technology — although it can generate excellent extra-oral images (panoramic, cephalometric, etc.) — still exposes considerably more than a simple panoramic or a cephalometric exposure; sometimes three times to several times more. Although it could substitute traditional extra-oral imaging, I don’t believe it should. Purchasing a cone-beam CT unit with the goal of replacing an existing panoramic and/or cephalometric machine in a dental or a dental specialty practice is not justified and not right. I really see CBCT technology as complementary to the existing imaging modalities and not really as a substitute of them.
As far as it concerns intraoral imaging, I do not think the image resolution of CBCT is such (at least not yet) that it can demonstrate fine details such as dental caries or early periapical pathology, etc. Moreover certain artifacts in CBCT images may obscure visualization of tooth structures around or underneath metallic restorations around implants, etc. In other instances, such as tooth fractures or presence of additional root canals in a tooth, the 3D perspective of CBCT may significantly contribute
Diogo: What do you think about the most recent guidelines from the National Council on Radiation Protection and Measurements? Is this something that affects dental practice?
Miles: I love them. They are overdue. There is some out of date information in them still, like the mention of “E” speed film. There is no real strategy by the ADA or the NCRP to educate dentists or the public about the proposed changes. But, they will become the standard in the next few years. Professor Robert Langlais and I wrote a summary article of their impact on all of our dental practices in Dentistry Today in September 2004. I’ve been asked so many questions about the report that it’s the best way I know to share the info with my colleagues. If anyone would like a copy, I can send it to them by e-mail – electronically! digitally! Just write me at [email protected].
Levato: The guidelines have changed; unfortunately, most dentists I speak to are unfamiliar with the agency and the recommendations, and outside of Dr. Miles’ and Langlais’ article in Dentistry Today this topic has been invisible.
Dalin: I am a firm believer in communicating with my patients. We discuss the need for any radiographs and make decisions jointly. The guidelines are just that: guidelines. Clinical decisions need to be made in the dental operatory between the dentist and patient.
Farman: These are already outmoded but have elements to recommend (e.g. rectangular collimation for intraoral radiography). The biggest area that needs to be introduced is 3D imaging (e.g. cone beam volumetric tomography).
Angelopoulos: The 2003 NCRP underlined once more radiation safety measures that have been taught for a number of years: The use of long and rectangular cones, the use of fast image receptors (film or digital) in order to ensure lowest exposure to the patient based on the ALARA concept. It is the first time that digital receptors are addressed by this body. This report also mentions that the use of lead aprons in dental offices may not be needed as long as all precautions addressed above (fast receptors, long and rectangular cones etc) are taken under consideration. I hope this will not be misinterpreted. The utilization of long and rectangular cones are not that popular and the vast majority of dentists in US are still using slower types of film.
Diogo: Let’s talk about DICOM. Is it working?
Levato: There has been a great deal of work by the ADA DICOM workgroup 22, led by Dr. Farman over the last three years, and we have a system and structure in place. Now we just need to teach dentists to use it in sharing digital radiographic images.
Miles: I’ll let Dr. Farman answer that one. He’s been a major factor behind the ADA’s push to educate our colleagues about it and advise (read goad) the commercial industry into adoption. It’s inevitable, appropriate and overdue. Everyone must learn about DICOM, a communication standard to help us all. Read about it. Where else?
ChristensenI think it’s too early to tell.
Dalin: The DICOM standard sounded like a good idea … a way to standardize images between all of the manufacturers. There does not seem to be a large amount of urgency to get this accomplished. I do like having the ability to choose the type of file that I can send off to others. This can be in DICOM format or a TIFF format.
Angelopoulos: It’s working much better than a few years past. I think dental imaging still lags behind medical imaging as far as it concerns the ease and convenience of imaging data exchange and data sharing. The available dental PACS (picture archiving and communication systems) storing DICOM images are only a handful. My friend and respected colleague on the field, Dr. Farman, would be the most knowledgeable to respond.
Farman: I am biased as I am the ADA voting representative to the international DICOM Standards Committee and Cochair DICOM WG 22 (Dentistry). Obviously, if images need to be exchanged there needs to be a standard, and DICOM is the one recognized standard for diagnostic image formats for medicine, dentistry and veterinary medicine. This standard provides not only for image interoperability but also for tags including patient identification, indication of lack of manipulation, etc. The industry can provide DICOM images and has shown this at consecutive ADA Annual Sessions on six occasions now. This software is provided to VA, DoD, etc. as a requirement, but is not yet universally promoted for general dental practice. My hope is that dentists will not need to check for DICOM as it will become universal. DICOM WG 22 has been involved in three supplements to the Standard over the past three years and has a further supplement nearing completion (structured display).
DICOM becomes indispensable with 3D/cone-beam CT if one wishes to interact with providers of virtual and real surgical models and surgical positioning stents.
Diogo: For most dentists, talk of DICOM, etc. is academic. For them — or for those not caught up on price or resistance to change — the question on digital comes down to one thing: Will digital radiographs help improve the range of quality images?
Miles: My shortest answer yet. YES, but you cannot use a cookbook approach. One digital solution does not fit all. Dentists must educate themselves and do their due diligence. If they do, they’ll finally see the light.
Levato: There are a number of requirements to produce excellent radiographs, and in clinical practice the variability is all over the board. I believe that digital radiology will give a better range of acceptable images if the hardware components are balanced, since there are fewer steps involved. A major advantage of direct digital radiology is that the image is readily available and can be immediately retaken if it is inadequate. The ability to produce exceptional film and digital radiographic images both require an understanding of the anatomy, size, positioning, radiographic principles, and the medium used. Dentists who insist on excellent film images can also set the same standards to produce exceptional digital images by providing the right hardware, software and training for their staff.
Christensen: Possibly; but operator variability will still provide a lot of good and bad radiographs.
Dalin: The wide disparity of quality of conventional dental radiographs stems from the differences in developing techniques. Some use automatic processors at very high temperatures for speed, and this lowers the quality of the final image. Some do not use the correct time when developing films. This too will alter the quality of the final film image. With digital radiography, you get a very consistent image, time after time. There are no variations because of chemistry or time issues.
Farman: Any system can be misused through poor exposure of geometric discrepancies, lack of calibration of sensors or display. Dentists who were sloppy with film will probably be sloppy with digital systems… and my guess is that such individuals will also provide suboptimal diagnoses, treatment plans and treatments for their patients. Digital imaging does remove the processing room errors from chemical processing. Conventional imaging does not permit 3D applications and so does not permit the present paradigm shift in dental practice for state of the art patient care.
Angelopoulos: There are a great deal of variables involved in radiographic image quality (the way a radiograph looks the moment it reaches the clinician’s light box). Some are related to the radiographic machine; others to the radiographic film and film processing. All of them have to be properly managed to produce radiographs of diagnostic quality. If one or more are neglected, the result will be a gradual loss of quality that may have an effect on the diagnosis derived from that radiograph and, most likely, on the treatment options based on that diagnosis. The variables are eliminated with digital radiography, leaving only the radiographic machine related issues (exposure settings) and technique needed be taken care of by the clinician. Eliminating variables that affect image quality will potentially lead to a better controlled image quality. This is exactly what digital radiography does. Now, add to that the various image processing options coming with digital radiography, and there is potential for the educated and trained user to extract more information than what it appears to be available at first view.